The present invention relates to a tilt device for a machine, particularly to a tilt device for a machine including a boom assembly and, more particularly, to a four-way tilt device for a mobile material handling machine.
The introduction of tree handling apparatus represented by U.S. Pat. Nos. 4,326,571; 4,565,486; and 4,583,908 obtained a significant advantage in the marketplace in selectively cutting from a row of trees. This arose due to its ability to rotate its platform throughout 360° within the overall width of the apparatus which is able to pass between adjacent rows of trees. Improvements to the initial machine represented in U.S. Pat. No. 4,326,571 included the ability to maintain the platform level while the apparatus worked on slopes such as mountain sides.
However, even such excellent devices have experienced some limitations for which further improvement was needed. In particular, a circular base is mounted below a turntable on which the platform is mounted, and upper ends of two rams are attached to the circular base to tilt the platform by moving the rams in an extending direction or a retracting direction. Two additional rams are mounted between the circular base and the frame. The overall height of the apparatus is relatively high and, thus, results in limitation such as the ability to pass under some bridges when being transported on trucks. Furthermore, the circular base is heavy and expensive and restricts access for maintenance.
A need exists for a tilt device for a machine such as a material handing machine that has a low profile while allowing tilt of the mounting plate and allowing easy maintenance of the machine as well as 360° rotation of components mounted to the mounting plate.